In order to lock a steering shaft of a steering column so as to prevent unauthorized use of the vehicle, it is possible to use a lock including a locking member guided, relative to a structure fixed in rotation, between a retracted position and a locking position in which it performs positive locking with a matching member connected in rotation to the steering column, to prevent the steering column integral with the steering wheel from rotating.
When the height of the steering column is adjustable by tilting around a transverse horizontal pivot axis perpendicular to the axis of rotation of the steering shaft, the locking member is most often mounted so as to follow the tilting movement. In practice, the steering shaft is mounted in a tube body, which provides guiding of the steering shaft in rotation around its axis, and which in turn is articulated to a fixed bracket so as to ensure the desired tilting movement around the pivot axis. The lock is then integrated into the tube body. This arrangement of the lock increases the mass of the moving part of the steering column, increases its bulk and requires electric control cables long enough to follow the tilting movement of the moving part. To resolve these problems, it has been proposed in document DE 198 09 294 to position the lock on a fixed bracket. In the case at hand, the locking member is made up of a bolt and the matching member of a toothed crown supported by the steering shaft. The end of the bolt is curved, to ensure satisfactory engagement in the toothed crown in the locking position, irrespective of the incline of the steering column.
However, this arrangement is only satisfactory for small angular variations during tilting of the shaft, since for larger variations, the bolt risks escaping from the toothed crown. In practice, it has been abandoned and is implemented little or not at all.